The invention relates to an indicating system for an automatic electronically or electrohydraulically controlled motor vehicle transmission, which is equipped with a selector lever for the preselection of individual or several automatically shiftable driving gear steps and which permits a fully automatic operating mode for the gear step selection or a semi-automatic operating mode in which the automatically shiftable gear steps may be preselected manually.
As a rule, automatic motor vehicle transmissions are equipped with a selector lever by means of which a vehicle driver can preselect individual or several automatically shiftable gear steps. In this case, the preselected gear step is made visually observable by means of indicating elements which are characterized for this purpose by alphanumerical signs or symbols (e.g., P, R, N, D, 3, 2, 1). Frequently, the indicating elements, in the manner of a scale, are arranged either in parallel to a shifting path in which the selector lever is guided or inside a switching panel such as inside a combination instrument together with several indicating instruments.
An automatic motor vehicle transmission having an indicating system of this type is described in Bosch "Technische Berichte", 7/1983)4, on Pages 160 to 166. However, in addition to a fully automatic operating mode for selecting the gear steps, this transmission also has a semi-automatic operating mode in which the individual gear steps of the forward gears (gear steps 1, 2, 3 and 4) may be preselected manually. The switching between the two operating modes takes place by means of a separate program selection switch.
Since, however, even during the manual operating mode, a shifting into a preselected gear step takes place only when the driving engine of the motor vehicle, after the shifting of the gears, runs within plausible predetermined rotational speed limits, the preselected gear steps and the gear steps into which the shifting took place may deviate from one another.
It is therefore an object of the invention to provide an indicating system for an automatic motor vehicle multi-speed transmission which indicates to a vehicle driver a momentary state of the transmission without noticeably diverting his attention from the traffic situation.
The invention is carried out by means of an arrangement wherein said indicating system includes:
first displaying means for displaying the preselected driving gear steps corresponding to the selector lever position by means of first indicating elements marked by alphanumerical symbols, and
second displaying means for displaying an actual shifted gear step (I, II, III, IV), said second displaying means including second indicating elements which are viewable separately from and simultaneously with the first indicating elements. In especially preferred embodiments the first and second indicating elements are disposed close to but spared from each other.
The principal advantages of the invention are that an indicating system is provided which indicates the condition of the transmission, particularly the preselected and shifted driving step or gear step, to a vehicle driver without noticeably diverting his attention from the traffic situation. In addition, the indicating system permits a simple and effective differentiation with respect to the mode in which the transmission is operating (fully automatically or semi-automatically), and its construction is also very simple. As a result of the low required expenditures, the indicating system arrangement is also suitable for the retrofitting of existing indicating systems.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.